Determination of eltanolone in human plasma by high-performance liquid chromatography

A high-performance liquid chromatographic method for the determination of eltanolone in plasma has been developed. Plasma samples containing eltanolone were diluted with acetonitrile to precipitate plasma proteins, and derivatized with 2,4-dinitrophenylhydrazine before direct injection onto a C18 column. The mobile phase was acetonitrile-water (70:30, v/v) containing 0.1% trifluoroacetic acid and detection was by UV absorbance at 367 nm. The quantitation limit was 0.020 microg/ml. The method has proven to be rapid, precise and sensitive in the range of concentrations found during and following intravenous anaesthesia.